1. Field of the Invention
The present invention relates to pipe handling systems for handling a tubular pipe. More particularly, the present invention relates to pipe pick-up and lay-down systems for use in drilling operations.
2. Background of the Related Art
In the drilling of oil and gas wells, it is known to employ various types of tubular pipe. Such pipes include drill pipe, drill collars, production tubing, well casing, and riser pipe. Such pipe is delivered to the drilling rig, and laid in individual joints horizontally upon a pipe rack. In the case of land wells, the pipe is typically delivered by a flat-bed truck. For offshore drilling, the pipe is delivered by barge or on a large floating vessel.
In order to use the pipe on the drilling rig, it is necessary to transport the pipe from the pipe rack to the rig floor. However, picking up and laying down drill pipe, casing and other tubular goods presents certain hazards to personnel on the rig floor. In addition, the manual handling of pipe, even with the assistance of wirelines, creates a risk that the pipe threads may be damaged. These concerns are magnified by the ever-increasing height of rig floors necessitated by the drilling of deeper wells.
Various patents have issued which provide pipe pick-up and laydown systems. These systems typically involve the use of wirelines or cables to transport pipe from a pipe rack or truck bed to the rig floor. Such patents include:
U.S. Pat. No. 4,491,450 issued to George on Jan. 1, 1985;
U.S. Pat. No. 4,054,310 issued to Crocker on Oct. 18, 1977;
U.S. Pat. No. 4,099,630 issued to Beck on Jul. 11, 1978; and
U.S. Pat. No. 4,082,193 issued to Teague on Apr. 4, 1978.
These patents disclose systems that, while commonly used, require manual manipulation of pipes.
Other patents have attempted to reduce the involvement of rig hands in the handling of pipe by providing a trough for lifting pipe from the pipe rack to the rig floor. Such patents include:
U.S. Pat. No. 4,235,566 issued to Beaman, et al. on Nov. 25, 1980;
U.S. Pat. No. 4,054,310 issued to Thompson on Sep. 13, 1983; and
U.S. Pat. No. 4,552,498 issued to Dysarz on Nov. 12, 1985.
However, these systems are not readily adaptable to rigs of varying heights. In this respect, higher rig floors create steeper angles of approach from the catwalk or pipe handling area to the rig floor. If the angle of approach is too steep, the upper end of the joint of pipe will be too high above the rig floor for a worker standing on the floor to safely reach. Therefore, means are required to raise the rear end of the pipe to lower the angle of approach for the upper end of the pipe with respect to the elevated rig floor. It is thus desirable to be able to lift the pipe from the rear portion so as to reduce the angle at which the pipe is fed onto the rig floor.
U.S. Pat. No. 4,486,137 issued to Buckner on Dec. 4, 1984 provides a machine that lifts a pipe trough from the rear; however, a cable is apparently still required for lifting the front end of the trough to the rig floor.
Therefore, it is desirable to provide a pipe pick-up and laydown system that includes a V-Door ramp of adjustable height so as to adapt the pick-up and laydown system to rigs of various heights. Still further, it is desirable to provide a pick-up and laydown system that has improved mobility for quickly delivering the system to the wellsites. Further still, a need exists for a system that enables pipe to be picked up from a pipe rack, placed in a trough, and the trough and pipe moved to a position on the drilling rig floor without the need for a cable or wireline attachment to the pipe.
There is yet a further need for such a system that delivers pipe over the rig floor a greater distance than known systems. In this regard, it is desirable to deliver pipe as close as possible to the wellbore being formed. In this manner, the rear end of the delivered pipe does not swing as much when the pipe is lifted from the pickup and laydown system.
In addition, there is a need for a pipe-handling machine that can be operated solely through hydraulic power. There is further a need for a pipe manipulation system having a greater capability for adjusting the angle at which pipe is presented to the rig floor. Finally, a need exists for a pipe pick-up and laydown system that is essentially remotely operable.